How Do I Prepare for Quarterly Estimated Tax Payments?

When you work for an employer, tax is taken out of every paycheck. When you run a business, that automatic system disappears. Nobody withholds tax from your sales, your client payments, or your marketplace payouts, so the responsibility to pay during the year falls to you. Quarterly estimated tax payments are how the system keeps self-employed people current.

Many new business owners find out about estimated taxes only when they file their first return and discover both a large balance and an underpayment penalty. The good news is that the process is manageable once you know the deadlines, the safe harbor rules, and a simple routine for setting money aside.

This guide walks through who has to make estimated payments, the key dates, how to calculate what you owe, how to pay, and how to stay organized throughout the year. Tax rules, thresholds, and dates change and vary by state, so confirm current figures with the IRS, your state tax agency, or a qualified professional.

1. What Are Quarterly Estimated Taxes?

Estimated taxes are payments made during the year toward your expected income tax and self-employment tax bill. The U.S. tax system is pay-as-you-go, which means tax is due as income is earned, not only when you file a return.

• They cover federal income tax on business profit and other untaxed income
• Self-employed people also owe self-employment tax, which funds Social Security and Medicare
• Payments are reported on your annual return as tax already paid
• Despite the name, the four payment periods are not equal in length

2. Who Needs to Make Estimated Payments?

As a general rule, you may need to make estimated payments if you expect to owe $1,000 or more in federal tax for the year after subtracting withholding and credits. Common situations include:

• Sole proprietors, single-member LLC owners, and freelancers
• Partners in a partnership and owners of S corporations who receive profit not covered by withholding
• Online sellers receiving marketplace or payment processor payouts
• People with significant interest, dividends, rental income, or capital gains
• C corporations, which follow separate estimated tax rules for corporations

3. Due Dates for the 2026 Tax Year

*Dates move to the next business day when they fall on a weekend or holiday. State due dates may differ, so check your state's schedule. If you are reading this in fall 2026, the fourth payment is the one coming up.

4. Income Covered by Each Payment Chart

The payment periods are uneven. The chart below shows how many months of income each payment covers, which is why a seasonal business should not simply divide the year into four equal parts.

5. How to Calculate Your Payments

There are two common approaches. Pick the one that matches how predictable your income is.

• Project your current-year tax: estimate your net profit for the year, subtract deductions, calculate income tax and self-employment tax, and divide by four. This is more accurate if income is changing.
• Use last year's tax: take your prior-year total tax from your return and divide by four. This is simpler and gives you safe harbor protection if you meet the rules below.

6. Safe Harbor Rules

You can generally avoid an underpayment penalty by meeting one of these safe harbor tests:

Illustrative example: If last year's total tax was $12,000, the prior-year safe harbor means paying $12,000 across the year, or $3,000 per payment. If you project this year's tax at $14,000, the 90% test means paying $12,600, or $3,150 per payment. You can use whichever is lower and still meets a safe harbor. These figures are examples only.

*Thresholds and special rules, such as those for farmers and fishers or higher-income taxpayers, can change. Confirm current rules before relying on a safe harbor.

7. How to Pay

• IRS Direct Pay: pay directly from a bank account with no sign-up
• IRS online account: pay and view your payment history
• EFTPS: the Electronic Federal Tax Payment System, useful for scheduling payments in advance
• Debit or credit card: through approved payment processors, which charge a fee
• Mail: a check with a payment voucher from Form 1040-ES

Keep a confirmation for every payment and record it in your books, so it is easy to credit on your return. A professional preparer through our tax preparation services can also confirm that all payments were applied correctly.

8. State Estimates, S Corporations & Payroll

• State estimates: many states, including New Jersey, require their own estimated payments with separate forms and sometimes different dates
• S corporation owners: if you are paid a salary through payroll, you may be able to adjust your W-4 withholding to cover your tax instead of making large separate estimates, which is worth discussing with a professional (see Best Entity Type for E-Commerce Tax Savings)
• Employers: estimated tax for the owner is separate from payroll tax deposits for employees, so keep both on your calendar (see Payroll Management Services in USA)
• Sales tax: collected sales tax belongs to the state and is not part of your income tax estimate, so track it separately (see Non-Compliant to Fully Compliant Sales Tax Filing)

9. Quarterly Preparation Checklist

• ☐ Close and reconcile your books for the period
• ☐ Review year-to-date profit and compare it with your projection
• ☐ Update your estimate of full-year tax if income has changed
• ☐ Decide which safe harbor you are using
• ☐ Calculate the federal payment and any state payment
• ☐ Make the payment before the due date and save the confirmation
• ☐ Record the payment in your books
• ☐ Confirm your cash reserve covers the next payment

10. Setting Cash Aside Without Stress

The hardest part of estimated taxes is often having the cash ready. A few habits make it easier:

• Open a separate savings account just for taxes
• Transfer a set percentage of each deposit or payout, based on your projection, as soon as money arrives
• Review the percentage each quarter and adjust as profit changes
• Use financial planning & analysis and financial modeling to forecast tax and cash flow together
• Know your profit baseline through a break-even analysis so you know how much of each sale is actually profit

11. Common Mistakes

• Forgetting self-employment tax and only planning for income tax
• Skipping early payments and trying to catch up late, which can still draw penalties for the earlier periods
• Using revenue instead of profit to estimate tax
• Missing state estimates because only the federal payment is on the calendar
• Spending the tax money because it sits in the main operating account
• Not updating the estimate after a big sales jump or a major purchase
• Relying on messy books, which makes the whole calculation unreliable

12. How Professional Support Helps

Estimated taxes work best as a routine tied to your bookkeeping and planning. At CashBook Accounting, we help business owners with:

• Tax preparation and projections that set accurate quarterly payments
• E-commerce bookkeeping that delivers monthly profit numbers you can plan around
• Books clean-up for owners who are behind and need reliable figures
• Payroll services that coordinate owner pay with tax planning (see also How Payroll Outsourcing Saved a 100-Person Company 200 Hours/Year)
• Sales tax services so collected tax never gets mixed with your income tax savings
• Financial planning & analysis to forecast tax and cash needs by quarter
• Financial modeling to test how growth changes what you will owe

If you also have employees, see Do I Have to Provide Workers' Compensation Insurance? for another obligation tied to payroll.

13. Frequently Asked Questions

14. Related Articles

Disclaimer: This article is for general informational purposes only and does not constitute tax or legal advice. Tax rules, thresholds, and deadlines change and vary by state and situation, and the figures in examples are illustrative. Consult a qualified tax professional such as the CashBook Accounting team for guidance specific to your business.